1. Technical Field
The present invention relates to a substrate processing apparatus that processes a substrate in a processing chamber, and particularly relates to the substrate processing apparatus, with a transfer chamber connected to the processing chamber.
2. Background Art
In the substrate processing apparatus, with the processing chamber and the transfer chamber being connected to each other, in order to prevent a natural oxidization of a substrate, the transfer chamber is set in an air-tightly closed structure, and an inside of the transfer chamber is replaced with inert gas and there are provided a purge gas inlet tube and an exhaust tube for maintaining an oxygen concentration to a prescribed value or less.
In order to prevent adhesion of a natural oxide film on the substrate, the oxygen concentration is maintained to a prescribed value or less and the inert gas is circulated in the transfer chamber.
However, when a surface of the substrate is examined after processing the substrate in the processing chamber, an organic matter is adhered thereto in some instances. It is found that such an organic matter is generated by heating wiring of the processing chamber at the time of high temperature processing, and by diffusion of the organic matter into the transfer chamber together with a high temperature atmosphere at the time of unloading the wafer, such an organic matter is adhered to the substrate. When the film is deposited without cleaning the organic matter, a film grows from a part to which a contaminated substance such as an organic matter, etc, is adhered. Therefore, a local distortion of crystal lattice and non-uniformity of an in-surface film thickness are generated in that case.
However, in order to change so as to prevent the adhesion of the organic matter to the substrate, rather than preventing the adhesion of the natural oxide film to the substrate, an apparatus structure and an apparatus parameter must be changed. Accordingly, since a location of the apparatus is limited, the apparatus must be operated so that a function of preventing the adhesion of the natural oxide film to the substrate by the same apparatus and the function of preventing the adhesion of the organic matter onto the substrate are switched for each processing.